Completion fluid friction reducer

ABSTRACT

A method and composition for reducing a coefficient of friction are disclosed. In an embodiment, a method for reducing a coefficient of friction between two surfaces in a borehole includes preparing a mixture comprising a primary lubricating agent, a primary surfactant, a spreading agent, and an aqueous fluid. The method also includes pumping the mixture into the borehole such that the mixture contacts the two surfaces and reduces the coefficient of friction for the two surfaces.

RELATED APPLICATIONS

This application is a divisional application of pending U.S.Nonprovisional patent application Ser. No. 15/045,001, filed on Feb. 16,2016, which is specifically incorporated by reference in its entiretyherein.

BACKGROUND Field of the Invention

This invention relates to the field of completion fluids for drillingapplications, and more particularly to the field of reducing thefriction between similar or dissimilar surfaces using an aqueous-basedcompletion fluid disposed between the similar or dissimilar surfaces.

Background of the Invention

Drilling horizontally within an oil and gas reservoir can potentiallyproduce a more productive well, because a horizontal well may allow foraccess to larger areas of an oil- and gas-bearing formation. As such,the longer the horizontal section of the well, the more productive thewell may be. For this reason, it has become increasingly common to drillhorizontally in many oil- and gas-bearing formations as well as utilityand mining applications.

Increasing the length of the horizontal section of a borehole may bedifficult when the length of the horizontal section surpasses the lengthof the vertical section. Further, the insertion of conduits, such as adrill pipe, may become increasingly difficult as the horizontal sectionis lengthened. For example, as the drill pipe is pushed further into theborehole, the amount of contact between it and other surfaces increases,and thus so would the amount of friction between the drill pipe and theother surfaces. Thus, the ability to push or rotate the drill pipe inthe wellbore may become limited as the friction increases. Friction mayalso be present between a conduit and wellbore tools/wellbore materialsinserted into the conduit. For example, wires or cables may be pushed orpulled into a conduit only so long as the amount of friction between thewires/cables and the conduit is low enough to allow for the wires/cablesto be pushed or pulled. As discussed above, friction between two similaror dissimilar surfaces may increase faster in horizontal sections of aconduit relative to vertical sections of the conduit.

A specific example of the difficulty of drilling a horizontal sectionmay be illustrated by the process of drilling bridge plugs from thecasing. The drilling of bridge plugs is often performed with a fluidmotor and bit on the end of a section of coiled tubing. An aqueous-basedfluid may be pumped down the tubing, through the motor and bit, and backup the annulus inside the casing. The friction between a section ofcoiled tubing and the casing in the horizontal section of the boreholemay become equal to the force available to move the coiled tubing alongthe horizontal section, at which point further drilling may not bepossible.

As discussed, one method of reducing friction in oil, gas, and miningoperations is to push a conduit with a mechanism that would drive theconduit into the borehole or well. This pushing may be accomplished byany mechanism that is capable of delivering a sufficient amount of forceto the conduit such that the conduit is pushed into the borehole. Thismay be referred to as “snubbing the pipe.” In utility boring or miningoperations, cables may be attached to the drill string to pull theconduits into or out of the borehole so as to overcome the frictionbetween the conduit and the borehole. Further, in some horizontaldrilling applications, rotating the conduit at a high enough RPM mayreduce the amount of frictional contact between the conduit and anysurfaces it contacts. This is commonly done during drilling and boringoperations and may allow for longer horizontal sections to be drilled.However, not all conduits can be rotated. For example, when a jointedpipe is used, the pipe may be rotated along with the bit, and thefriction resisting movement of the pipe along the borehole may bedecreased. However, when coiled tubing is used, the coiled tubing cannotbe rotated, and the friction resisting movement of the tubing along theborehole may be increased. Further, even when using jointed pipes, wellswith directional changes resulting in “doglegs” or a crooked borehole,may restrict the amount of rotation that may be used. Moreover, whenusing these physical methods to reduce friction, friction may continueto build as the borehole is drilled, and the conduit is inserted deeper.Thus, eventually enough friction may be present to prevent furtherinsertion or extraction of a conduit from the borehole. This effectivelymeans that drilling rigs may sometimes drill longer horizontal sectionsthan completion equipment can complete.

Friction reducers have proven effective in reducing the coefficient offriction between two metal substrates. Some examples may include thedeposition of polymer particles onto a metal substrate. In theseexamples, the oil must have a charge association. However, this approachmay be ineffective when there are not two metal substrates present toprovide the deposition sites, or when fluid conditions, such as thefluid pH, change when in use, and these changed fluid conditions alterthe charge association and prevent film buildup or transport of thefriction reducers.

Consequently, there is a need for an organic nonhazardous biodegradablefriction reducer that is not charge specific, does not requiremechanical deposition to reduce the coefficient of friction, is usablebetween any types of media, and can function in any water conditionregardless of the pH of the water or the presence of suspended ordissolved solids.

BRIEF SUMMARY

These and other needs in the art are addressed in an embodiment by amethod for reducing a coefficient of friction between two surfaces in aborehole. The method includes preparing a mixture comprising a primarylubricating agent, a primary surfactant, a spreading agent, and anaqueous fluid. The method also includes pumping the mixture into theborehole such that the mixture contacts the two surfaces and reduces thecoefficient of friction for the two surfaces.

These and other needs in the art are addressed in other embodiments by apumpable friction reducing fluid composition. The composition includes aprimary lubricating agent, a primary surfactant, a spreading agent, andan aqueous fluid.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter that form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand the specific embodiments disclosed may be readily utilized as abasis for modifying or designing other embodiments for carrying out thesame purposes of the present invention. It should also be realized bythose skilled in the art that such equivalent embodiments do not departfrom the spirit and scope of the invention as set forth in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

These drawings illustrate certain aspects of some of the examples of thepresent method and should not be used to limit or define the method.

FIG. 1 is an overall view of a horizontal well configuration inaccordance with present embodiments.

FIG. 2 is a sectional view of a horizontal portion of the horizontalwell with coiled tubing located within the casing of the well inaccordance with present embodiments.

FIG. 3 is an overview of the process of linking of a hydrophobic tail ofa lubricating agent with the hydrophobic tail of another lubricatingagent in accordance with present embodiments.

FIG. 4 is a perspective view of the friction-testing device used to testfluids in accordance with present embodiments.

FIG. 5 is a graph of the results of tests using the test apparatus ofFIG. 4 in accordance with embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates a typical coiled tubing drilling apparatus in ahorizontal well 100 having wellhead 10. Support 16 holds a reel ofcoiled tubing 18, which is guided over curved support 11 into the well100. Wellhead 10 may include a blowout preventer, a snubbing mechanism,or other conventional equipment. The well 100 is cased with casing 26that extends within the well bore 105 through formations 20 in thevertical section 110 of the well and through formation 28 in thehorizontal section 115.

For certain well completion processes, such as drilling bridge plugsfrom casing 26, coiled tubing 18 is lowered into the well 100 and entersthe horizontal section 115 of casing 26, which is normally cemented information 28. Turbine or motor 17 and bit 19 may be attached to thedistal end of the coiled tubing 18 to drill out devices such as bridgeplugs (not shown) that have been inserted into the horizontal section115 of the casing 26. For drilling applications, a fluid is pumpedthrough coiled tubing 18, motor 17 and bit 19 and returns to thewellhead 10 through the annulus 120 (illustrated in FIG. 2) betweencoiled tubing 18 and casing 26.

As coiled tubing 18 is pushed through the horizontal section 115 of thecasing 26, contact may occur at points 31-35, shown in FIG. 2. Contactat contact points 31-35 may be between any types of media including anysimilar or dissimilar media that may be inserted into the well 100. Forexample, contact may be metal-to-metal contact, plastic-to-plasticcontact, metal-to-plastic contact, etc. Friction increases the forcerequired to place the coiled tubing 18 in the well 100 and may limit thelength of the coiled tubing 18 that may be placed in the horizontalsection 115 of the casing 26.

In embodiments, a friction reducer may be introduced to the well 100 toreduce the friction at contact points 31-35. The friction reducer may beused to reduce the coefficient of friction between the two similar ordissimilar media which may form contact points 31-35. In embodiments,the friction reducer comprises a primary lubricating agent. The primarylubricating agent comprises a tall oil fatty acid, a tallow oil fattyacid, or a combination thereof. Tall oil fatty acids as defined herein,are any fatty acid produced via the Kraft process of wood pulpmanufacture. One of ordinary skill in the art would understand the Kraftprocess which generally involves treatment of wood chips with a mixtureof sodium hydroxide and sodium sulfide that breaks the bonds that linklignin to the cellulose. In some embodiments, the tall oil fatty acidmay have a partially unsaturated C18 backbone. Examples of a tall oilfatty acid include, but are not limited to palmitic acid, palmitoleicacid, stearic acid, oleic acid, linoleic acid, or a combination thereof.Tallow oil fatty acids as defined herein, are any fatty acid producedfrom rendering beef or mutton fat. One of ordinary skill in the artwould understand that rendering beef or mutton fat generally involves abatch or a continuous process in which an amount of tissue material isheated in a steam-jacketed vessel to drive off the moisture andsimultaneously release the fat from the fat cells. Examples of a tallowoil fatty acid include, but are not limited to palmitic acid,palmitoleic acid, stearic acid, myristic acid, oleic acid, linoleicacid, linolenic acid, or a combination thereof. The tall oil fatty acidor tallow oil fatty acid may be used in a crude or refined form. Thefriction reducer may also comprise optional additional lubricatingagents, for example, secondary or tertiary lubricating agents. Theoptional additional lubricating agents may comprise one of the exampleprimary lubricating agents discussed above, or may comprise alubricating agent that is not a tall oil fatty acid, a tallow oil fattyacid, or a combination thereof.

In embodiments, the friction reducer comprises a primary surfactant. Theprimary surfactant comprises a nonionic polyethylene glycol surfactantwith a hydrophile/lipophile balance between 9 to 14 and a molecularweight in a range of about 200 to about 600. Suitable examples include,but are not limited to poly(ethylene glycol) monooleate, poly(ethyleneglycol) dioleate, poly(ethylene glycol) monolaurate, poly(ethyleneglycol) dilaurate, or a combination thereof.

In embodiments, the friction reducer comprises a spreading agent. Thespreading agent comprises a transesterified lipid. Suitable examplesinclude, but are not limited to methyl canolate, methyl caprate, methylcaprylate, methyl coconate, methyl lardate, methyl laurate, methylmyristate, methyl oleate, methyl palm kernelate, methyl palmitate,methyl soyate, methyl stearate, methyl tallowate, or a combinationthereof. In embodiments, the friction reducer may comprise the spreadingagent in a 4:1 to 1:4 ratio by weight percent with the primarylubricating agent. For example, the ratio of the spreading agent to theprimary lubricating agent may be about 4:1 by weight percent, about 3:1by weight percent, about 2:1 by weight percent, about 1:1 by weightpercent, about 1:2 by weight percent, about 1:3 by weight percent, about1:4 by weight percent, and so on. In a specific embodiment, thespreading agent may be present in the friction reducer in a 1:1 ratiowith the primary lubricating agent.

In optional embodiments, the friction reducer may comprise a secondarysurfactant. The secondary surfactant comprises a nonionic alkanolamidefamily member that is a reaction product of diethanolamine and a fattyacid. In optional embodiments, the secondary surfactant has ahydrophile/lipophile balance between 9 to 14 and a molecular weight in arange of about 200 to about 600. Suitable examples include, but are notlimited to cocamide diethanolamine, lauramide diethanolamine, oleamidediethanolamine, a soyamide diethanolamine, lauric acid diethanolamine,oleic acid diethanolamine, or a combination thereof. Where present, thefriction reducer may comprise the secondary surfactant in a 4:1 to 1:4ratio by weight percent with the primary surfactant. For example, theratio of the secondary surfactant to the primary surfactant may be about4:1 by weight percent, about 3:1 by weight percent, about 2:1 by weightpercent, about 1:1 by weight percent, about 1:2 by weight percent, about1:3 by weight percent, about 1:4 by weight percent, and so on. In aspecific embodiment, the secondary surfactant may be present in thefriction reducer in a 1:1 ratio with the primary surfactant.

In embodiments, the aqueous fluid may be added to the friction reducerprior to pumping the friction reducer into a borehole. The aqueous fluidmay be from any source. The aqueous fluid may comprise fresh water orsalt water. Salt water generally may include one or more dissolved saltstherein and may be saturated or unsaturated as desired for a particularapplication. Seawater or brines may be suitable for use in someapplications. The aqueous fluid may comprise any amount of dissolvedsolids and/or suspended solids. The dissolved solids and/or suspendedsolids may be from any source. The aqueous fluid may comprise any pH,for example, the aqueous fluid may comprise a pH of about 1 to about 14.Further, the aqueous fluid may be present in an amount sufficient toform a pumpable fluid. In certain embodiments, the aqueous fluid may bepresent in an amount in the range of from about 33% to about 200% byweight of the friction reducer. In certain embodiments, the aqueousfluid may be present in an amount in the range of from about 35% toabout 70% by weight of the friction reducer. With the benefit of thisdisclosure one of ordinary skill in the art should recognize theappropriate amount of aqueous fluid for a chosen application.

The components of the friction reducer may be added to the aqueous fluidin any order. Further, two or more of the components of the frictionreducer may be mixed before adding the aqueous fluid. The components ofthe friction reducer may be mixed in any order, for example the primarylubricating agent may be mixed with the primary surfactant. Thespreading agent may then be added to and mixed with this mixture. Theaqueous fluid may then be added to that mixture of the primarylubricating agent, primary surfactant, and the spreading agent to forman unstable oil-in-water emulsion. As an alternative example, theprimary surfactant may be added to the aqueous fluid and mixed. To thismixture, the primary lubricating agent and the spreading agent may beadded and mixed to form an unstable oil-in-water emulsion where theprimary lubricating agent comprises the dispersed phase, and the aqueousfluid comprises the continuous phase. Without limitation by theory, itis believed that not fully emulsifying the primary lubricating agent maybe important for achieving deposition of the micelles formed from theprimary lubricating agent on a surface to be lubricated, as discussed inmore detail below.

Without limitation by theory, it is believed that the nonionic nature ofthe surfactants allows the friction reducer to be used in a wide rangeof aqueous fluid conditions including fresh water sources such asmunicipal water supplies to rivers or lakes or heavily weighted brineand water containing high levels of total dissolved solids and/or totalsuspended solids. Moreover, it is believed that the hydrophile/lipophilebalance of 9 to 14 allows for the formation of suspended microscopicmicelles of the primary lubricating agent. In effect, the primarylubricating agent is evenly dispersed throughout the aqueous fluid inthe friction reducer, without being fully emulsified. The even dispersalof the primary lubricating agent also allows for an even deposition ofthe primary lubricating agent within the casing 26, formations 20 and28, coiled tubing 18, or any other surface in which the friction reducercontacts. The spreading agent may be used to increase micelle mobilitythroughout the aqueous fluid. The micelles comprise polar hydrophilicheads and long hydrophobic tails. The balance of the hydrophilic headsto the hydrophobic tails is precisely governed by thehydrophile/lipophile balance of the primary surfactant and, if present,the secondary surfactant. As explained below, a hydrophobic tail of theprimary lubricating agent contained within a micelle may be linked orbranched to a hydrophobic tail of another primary lubricating agent aswell as the hydrophobic tails of the primary surfactant and, if present,the secondary surfactant.

The nonionic characteristics of the primary and secondary surfactantsallow the friction reducer to be used in a wide range of aqueous fluidtypes, including those with high levels of dissolved solids and/or highlevels of suspended solids, with no perceptible negative effect onperformance. In some examples, the measured coefficient of frictionvalues have been shown to improve when used in an aqueous fluidcomprising elevated levels of dissolved solids. As mentioned above,certain types of dissolved solids may allow for the crosslinking of theCOOH group of the hydrophobic tail with divalent (e.g., Ca2+, Mg2+,Cu2+, Fe2+, Mn2+, etc.) and trivalent (A13+, Fe3+, Mn3+, B3+, etc.)cations present within the aqueous fluid. FIG. 3 illustrates the linkingof the hydrophobic tail 37 of a molecule of a primary lubricating agent38 with the hydrophobic tail 37 of another molecule of a primarylubricating agent 38. Upon introduction into the aqueous fluid, thehydrophilic head 39 of the molecule of primary lubricating agent 38dissociates and loses a hydrogen, leaving a corresponding COO— group.Free divalent and trivalent cations may then act as a bridge linking theCOO— groups from other molecules of primary lubricating agent 38 andalso any compatible primary and, optionally, secondary surfactants withCOO— (or other anionic) groups present. Molecule 40 is an example of twomolecules of primary lubricating agent 38 linked by a divalent cation.Molecule 41 is an example of three molecules of primary lubricatingagent 38 linked by a trivalent cation. This process may increase theamount of hydrophobic tails per molecule of primary lubricating agent38, which may in turn provide a stronger and more robust lubricatingboundary layer between any similar or dissimilar media. It is to beunderstood that the more impurities that are present the stronger andmore ridged the micelles can become due to the linking of thehydrophobic tails of the primary lubricating agent. Without the use ofnonionic surfactants with the properties disclosed herein, organizedmicelle formation may not occur, and hydrophobic tail linking may notoccur.

The cohesive force that promotes deposition of the micelles on a media'ssurface is due to the inherent nature of the hydrophobic tales migratingto and attaching to any available surface within the aqueous fluid body.The hydrophobic tales may then orientate themselves and attach at anangle (e.g., a 90° angle) relative to the surface, with the subsequentdeformation of the spherical shape of the micelle, such that the micellemay break apart as the hydrophobic tales attach to the surface, leavingthe hydrophilic heads facing the aqueous fluid body. The depositedmicelles create an extremely tenacious boundary layer between any of thesurfaces they contact, and this boundary layer may significantly lowerthe coefficient of friction between two surfaces. Ultimately, thiscomposition may allow an operator to convey a work string (e.g., coiledtubing 18 as shown in FIGS. 1 and 2) within the borehole with much lessrequired energy. This may in turn lessen the chance of sticking andgreatly improve the overall efficiency of a drilling operation.

This organic mixture has proven to be much more effective thanconventional chemistry in horizontal oil and gas well drilling andcompletion operations. Tests have been performed on an oil and gas well,and the rotational torque and weight of the pipe were compared toconventional chemistry. The mixture showed a twofold improvement infriction with one third of the volumetric dosage rates. This improvedperformance at lower dosage rates is substantial in reducing the overallcarbon footprint associated with the manufacturing, transportation,storage and application of these chemicals. It should also be noted thatduring these tests, water that had been produced from an oil and gaswell and containing high levels of suspended and dissolved solids, thatwould have normally been injection into disposal wells was used as theaqueous solution in which the mixture was applied into. This mixture hasproven effective not only in very turbid fluid conditions but within awide range of PH conditions.

The media lubricated by the friction reducer may be any such media asdesired, including similar (i.e. the same types of media) or dissimilar(i.e. different types of media). Without limitation, the media maycomprise metal (e.g., iron, steel, copper, aluminum, etc.); plastic(polypropylene, polyethylene, polyvinyl chloride, etc.); any and alltypes of rock (e.g., shale) which may occur in a formation (e.g.,formations 20 and 28 as illustrated on FIG. 1); wood; compositesthereof; or combinations thereof. In embodiments, the friction reducermay be used to lower the coefficient of friction of the two media.Without limitation by theory, this is believed to occur, because thefriction reducer may form a boundary layer between the surfaces of thetwo media, such that the amount of contact between the surfaces of thetwo media is reduced. For example, the friction reducer may be used tolower the coefficient of friction between a metal and a rock. As anotherexample, the friction reducer may be used to reduce the coefficient offriction between a plastic and a metal.

In embodiments, the friction reducer may be non-toxic at theconcentrations used in the disclosed examples. Non-toxic is definedherein as a product that does not produce immediate personal injury orillness to humans when it is inhaled, swallowed, or absorbed through theskin. As such, the friction reducer may be prepared for use with areduced risk to personnel as compared to the use of toxic frictionreducing compositions. The friction reducer may be biodegradable at theconcentrations used in the disclosed examples. Biodegradable is definedherein as any material which is capable of degradation by amicroorganism or through any other biological means. The frictionreducer may biodegrade at varying rates dependent upon the species oflubricating agent, surfactant, and spreading agent chosen, as well asthe conditions present to induce biodegradation. Thus, the frictionreducer may be placed and/or disposed on the surface or within aborehole, with a reduced risk of forming a permanent deposit of thefriction reducer on the surface, on equipment, or otherwise within theborehole. The friction reducer may be biocompatible at theconcentrations used in the disclosed examples. Biocompatible is definedherein as the ability to be in contact with a living system (e.g,plants, animals, etc.) without producing an adverse effect. The frictionreducer may contact living systems without risk of damaging thosesystems and may therefore be used in operations and/or at concentrationsin which other friction reducers may not be used. For example, thefriction reducer may be used in operations where the risk of and thepotential damage caused by pollution may be elevated.

EXAMPLES

To facilitate a better understanding of the present claims, thefollowing examples of certain aspects of the disclosure are given. In noway should the following examples be read to limit, or define, theentire scope of the claims.

Example 1

An illustration of a device used to evaluate the performance of thefriction reducer disclosed herein is shown in FIG. 4. This bench-topfriction tester is manufactured by JUSTICE BROS.®, and is intended forevaluating the performance of lube oil additives. JUSTICE BROS.® is aregistered trademark of Justice Brothers, Inc. of Duarte, Calif. Force Fof a metal bar is applied to rotating metal bearing surface 51. Cup 52surrounding the bottom quarter of the rotating bearing surface providesa reservoir to hold the fluid being tested. Force F is applied to lever53 by placing weight 54 on one end of the lever. A 1-pound weightapplies a force of 100 psi to the bearing surface. The performance ofthe fluids is measured by observing the amperage draw of 110 voltone-quarter HP motor 55 used to rotate the bearing with a constant forceon the bearing. Amperage is recorded in 5-second intervals. The testingis complete when galling of the bearing surface is heard or currentdrawn by the motor reaches 10 amps.

A 200 gram sample was prepared by mixing a 0.5% solution of thecomposition given in Table 1 into distilled water and mixing in a 200 mLbeaker with magnetic stirring for 3 minutes.

TABLE 1 Component Amount by weight Hydrocarbon oil 91.2%   Ethylenebis-amide 5% Polyethylene Glycol 600 dioleate tallate 2% TEFLON ®Particles 1.8%  

The sample was then quickly poured into cup 52 (FIG. 4). While holdingthe weight off the static bearing surface, the unit was turned on toallow the solution to coat the bearing surface. After a brief time, arm53 was lowered to apply a force of 200 pounds on the bearing surfaces,and the timer was started. After completion of a test, the cup wasremoved from the tester and cleaned with isopropyl alcohol. The bearingsurfaces were removed and replaced with new ones. Tests were performedwith the mixture of Example 1 and with other fluids.

FIG. 5 is a graph showing the amperage drawn by the motor over a periodof time with different fluids in the test apparatus illustrated in FIG.4. Lines A, C, and D, represent results for products presently used forcompletions in the oil and gas industry. In a non-limiting example, theproducts presently used for completions represented by lines A, C, and Dmay include, FRAQ SLIQ 1911 and FRAQ SLIQ 3006 produced by RockwaterEnergy Solutions, ForceGlide produced by Force Chem Technologies, SlickFrog FR and Salty Frog FR produced by Greenwell Energy Solutions, andHE® 150 Polymer and LIQUID HE® 150 Polymer produced by Chevron PhillipsChemical Company and the like. HE® is a registered trademark of ChevronPhillips Chemical Company LP. Line B represents results for a mixture ofTEFLON® and water. TEFLON® is a registered trademark of the ChemoursCompany FC, LLC of Wilmington, Del. Line E represents results for thecomposition of Example 1.

The graph clearly indicates that products A-D resulted in an amperagedraw approaching 10 in a much shorter time period than that of thecomposition disclosed above and in Example 1. Compositions A-D led tocurrents approaching 10 amps in 20-30 seconds, whereas the formulationdisclosed here led to currents approaching 10 amps after 70 seconds.

Example 2

A well operator had set 10 bridge plugs inside casing in the horizontalsection of a well in Texas. Operations to drill the bridge plugs wereconducted using coiled tubing. The well had a vertical depth of about8,290 ft and had a measured depth of about 13,220 ft. Coiled tubing hadbeen used to drill all plugs but the bottom two plugs. Using aconventional friction reducing fluid, friction limited the ability todrill the last two plugs. The decision was made to try the oil phasecomposition disclosed herein. After adding the oil phase mixturedisclosed in Example 1 to water at rates of 1 or 2 gals per 10 bbls andcirculating the present fluid up the annulus outside the coiled tubing,the final two plugs were reached and drilled. In a second well drilledfrom the same pad as the first well, friction was higher than in thefirst, but all the plugs were successfully drilled from the well usingthe composition disclosed herein. The representative of the welloperator who was present during the drilling operations commented thathe did not believe all the plugs could have been drilled without the useof the materials disclosed herein.

The concentrations given in Example 1 may be varied over a broad range.The concentration of TEFLON® particles may range from about 1% by weightto about 8% by weight. The concentration of ethylene bis-amide may varyfrom about 1% to about 10%. Tests can be used to determine an effectiveamount of suspending agent. The concentration of surfactant may rangefrom about 1% to about 5%. Tests such as described above can be used todetermine an effective amount of surfactant.

The formulation of the present invention has also been found to inhibitcorrosion on metal surfaces. Pieces of ¼-in plate were cut into2-in×5-in strips and their surface ground to bare metal. Two were usedas a control and not coated with anything. One strip was sprayed with a10 lb/gal brine and one was not. Both were set outside in atmosphericconditions. Two of the strips were treated with a solution ofpolyacrylamide in water, which is the composition of fluids used in manycompletion, workover and fracturing operations. One of these was sprayedwith a 10 lb/gal brine and one was not. Both were set outside inatmospheric conditions. The other two strips were treated with oilcontaining the surfactant TEFLON® as disclosed herein. One was thensprayed with brine and one was not. Both were put outside in atmosphericconditions. After five days in atmospheric conditions, the stripstreated with the oil containing surfactant and TEFLON® disclosed hereinshowed corrosion (rust) on less than 15% of the surface, while the othersamples had rust on 100% of the surface area. The samples treated withthe polyacrylamide fluid showed no better corrosion resistance than thecontrol plates that had no treatment. Surface rust for the control platetreated with the 10 lb/gal brine was noticeably thicker than the onethat was not sprayed. This held true for both the control plate and theone treated with polyacrylamide. The surface area for both the controlplates and those treated with polyacrylamide had rust on 100% of thesurface area.

The corrosion tests show that the fluid disclosed herein providescorrosion protection to steel surfaces in a well after contact with thefluid. This means that the oil, surfactant friction reducer containingTEFLON® can be pumped on an intermittent basis to provide corrosionprotection and friction reduction on the surfaces of tubulars in a well.

The preceding description provides various embodiments which may containalternative combinations of components. It should be understood that,although individual embodiments may be discussed herein, the presentdisclosure covers all combinations of the disclosed embodiments,including, without limitation, the different component combinations, andproperties of the system. It should be understood that the compositionsare described in terms of “comprising,” “containing,” or “including”various components or steps, the compositions can also “consistessentially of” or “consist of” the various components and steps.Moreover, the indefinite articles “a” or “an,” as used in the claims,are defined herein to mean one or more than one of the element that itintroduces.

For the sake of brevity, only certain ranges are explicitly disclosedherein. However, ranges from any lower limit may be combined with anyupper limit to recite a range not explicitly recited, as well as, rangesfrom any lower limit may be combined with any other lower limit torecite a range not explicitly recited, in the same way, ranges from anyupper limit may be combined with any other upper limit to recite a rangenot explicitly recited. Additionally, whenever a numerical range with alower limit and an upper limit is disclosed, any number and any includedrange falling within the range are specifically disclosed. Inparticular, every range of values (of the form, “from about a to aboutb,” or, equivalently, “from approximately a to b,” or, equivalently,“from approximately a-b”) disclosed herein is to be understood to setforth every number and range encompassed within the broader range ofvalues even if not explicitly recited. Thus, every point or individualvalue may serve as its own lower or upper limit combined with any otherpoint or individual value or any other lower or upper limit, to recite arange not explicitly recited.

Therefore, the present embodiments are well adapted to attain the endsand advantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, and may bemodified and practiced in different but equivalent manners apparent tothose skilled in the art having the benefit of the teachings herein.Although individual embodiments are discussed, the disclosure covers allcombinations of all of the embodiments. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. Also, the terms in the claimshave their plain, ordinary meaning unless otherwise explicitly andclearly defined by the patentee. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope andspirit of those embodiments. If there is any conflict in the usages of aword or term in this specification and one or more patent(s) or otherdocuments that may be incorporated herein by reference, the definitionsthat are consistent with this specification should be adopted.

What is claimed is:
 1. A pumpable friction reducing fluid compositioncomprising: a primary lubricating agent; a primary surfactant; aspreading agent; and an aqueous fluid.
 2. The composition of claim 1,wherein the primary lubricating agent comprises a tall oil fatty acid, atallow fatty acid, or a combination thereof.
 3. The composition of claim1, wherein the primary lubricating agent comprises palmitic acid,palmitoleic acid, stearic acid, oleic acid, linoleic acid, myristicacid, linolenic acid, or a combination thereof.
 4. The composition ofclaim 1, wherein the primary surfactant comprises a nonionic surfactantcomprising a hydrophile/lipophile balance between 9 to 14 and amolecular weight in a range of about 200 to about
 600. 5. Thecomposition of claim 1, wherein the primary surfactant comprises apoly(ethylene glycol) monooleate, poly(ethylene glycol) dioleate,poly(ethylene glycol) monolaurate, poly(ethylene glycol) dilaurate, or acombination thereof.
 6. The composition of claim 1, wherein thespreading agent comprises a transesterified lipid.
 7. The composition ofclaim 1, wherein the spreading agent comprises methyl canolate, methylcaprate, methyl caprylate, methyl coconate, methyl lardate, methyllaurate, methyl myristate, methyl oleate, methyl palm kernelate, methylpalmitate, methyl soyate, methyl stearate, methyl tallowate, or acombination thereof.